SecureDNS for Mac

From Server Logistics:

SecureDNS is an implementation of the ISC BIND 9.2.1 software that runs in what is known as a "chroot environment". A chroot environment adds an extra layer of security by limiting a process to it's own portion of the filesystem. Should the process in question become compromised, then the attacker will only have access to the process's chroot environment and not the entire system. In the case of this software distribution, that portion of the filesystem would be /chroot/named. As with any security measure, a chroot environment is not 100% secure and can be circumvented by very experienced crackers under certain circumstances. But for most cases it will definitely help impede attacks on the host system. BIND 9 also includes support for DNSSEC, which also adds to the security of the name server.